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Beware when setting Manual focus on the DP1. A cautionary tale.

And this could be the same on the 2 and 3.

Of course the gurus around here will already have been there and got the t shirt.

I did not realise that the lens could be set beyond infinity. The infinity mark is inset a bit to the left and not at the extreme end of the scale - because that is where I should have been last night.

I was photographing the glorious coloured lights in Kew Gardens yesterday evening. Being dark the auto focus was struggling. Being a smart**** I decided to move to manual and crank the lens setting all the way along the scale to the right hand end. My eyesight is too 'old' to really see what is happening on the rear LED so I had no idea that all my shots were out of focus.

Luckily the first half of my evening's shoot is OK. Some missed but the auto focus got quite a few right. Every shot taken on Manual is for the junk folder.

I have now re-visited the camera and it seems that the lens should be set slightly to the left of the middle of the infinity symbol. I used a loupe on the LED and that OK button to enlarge the image. Had I done that last night instead of trying to be too quick/clever I would have doubled my number of keepers.

We live and learn - but maybe I am preaching to the already educated.

Tony
 

Tim

Active member
And this could be the same on the 2 and 3.

Of course the gurus around here will already have been there and got the t shirt.

I did not realise that the lens could be set beyond infinity. The infinity mark is inset a bit to the left and not at the extreme end of the scale - because that is where I should have been last night.

I was photographing the glorious coloured lights in Kew Gardens yesterday evening. Being dark the auto focus was struggling. Being a smart**** I decided to move to manual and crank the lens setting all the way along the scale to the right hand end. My eyesight is too 'old' to really see what is happening on the rear LED so I had no idea that all my shots were out of focus.

Luckily the first half of my evening's shoot is OK. Some missed but the auto focus got quite a few right. Every shot taken on Manual is for the junk folder.

I have now re-visited the camera and it seems that the lens should be set slightly to the left of the middle of the infinity symbol. I used a loupe on the LED and that OK button to enlarge the image. Had I done that last night instead of trying to be too quick/clever I would have doubled my number of keepers.

We live and learn - but maybe I am preaching to the already educated.

Tony
So just to confirm you are referring to the Sigma Merrills ? As there was no Sigma DP3 (non Merrill)
For the record I was not aware of this.

Thanks

Tim
 

Tim

Active member
Yes, Tim.

My Sigmas are Merrills.

Sorry to confuse you.

Tony
No complaint at all, many thanks for the info as I still have and use a DP2 Merrill occasionally and you could save me from having this issue.
The other consideration is that the DP2 which I also have may / likely behave the same also.

I don't use the old DP2 but I do still fawn over the images I have from it. Its unique in IQ and the only thing I find that comes close is the DP2 Merrill is the "Medium" quality setting.
IMO the medium has a little better overall IQ even if there is a loss of resolution.
 

foveon

Member
I think all or at least a lot of manual fokus lenses behave like this, the reported reason is to balance thermal expansion
 

xpatUSA

Member
I don't use the old DP2 but I do still fawn over the images I have from it. Its unique in IQ and the only thing I find that comes close is the DP2 Merrill at the "Medium" resolution setting.
IMO the medium has a little better overall IQ even if there is a loss of resolution.
Just so's you know, medium res involves the dreaded interpolation. The raw image, as seen in RawDigger, is half-height and full-width. SPP interpolates by 3/2 vertically and 2/3 horizontally. Also the in-camera JPEG engine of course.

Ted
 

Tim

Active member
Just so's you know, medium res involves the dreaded interpolation. The raw image, as seen in RawDigger, is half-height and full-width. SPP interpolates by 3/2 vertically and 2/3 horizontally. Also the in-camera JPEG engine of course.

Ted
And yet they look better and print better up to certain sizes !
I will investigate this myself, I question Rawdigger "interpretation" of the file.

Not interested in the in camera jpeg.
 

xpatUSA

Member
And yet they look better and print better up to certain sizes !
That doesn't affect the fact that med res is interpolated.

I will investigate this myself, I question Rawdigger "interpretation" of the file.
RawDigger does not "interprete" the raw image data. It shows it as it is:



I look forward to proof that clearly shows otherwise.

Not interested in the in-camera jpeg.
Nevertheless, the in-camera JPEG remains interpolated, just like SPP med res output.

Sounds like you're quite happy with med. res. interpolation.

The basic reason for the interpolation is that Foveon's VPS system can't do fractional binning:

Foveon - VPS

Ted
 
OP here.

Can we move this thread back to the use of Manual Focus please.

Three posts on something different don't seem to be generating much interest.

I say that purely for those who stumble across the the thread having had a Manual Focus problem.

Tony
UK
 
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